The photoacoustical technique is based upon a discovery by A. G. Bell (1880), according to which a substance which is periodically radiated with light emits a sound signal. The application of this effect in more recent times leads to development of "photoacoustic spectroscopy" (see A. Rosencwaig in "Optoacoustic Spectroscopy and Detection" Academic Press 1977) for which devices have been commercially available since 1977.
It is an object of the present invention to provide a heatable cell for this photoacoustic process, which heretofore was conducted at room temperature.